1. Technical Field
The present invention relates to an instrument for a vehicle, such as a combination meter to be mounted on a vehicle.
2. Background Art
There is known an instrument for a vehicle in a form in which a translucent display design formed in a dial is illuminated with illumination light from behind the dial. In such an instrument for a vehicle, a display design is formed by white blanking or transparent color printing on the surface of a body of a dial formed out of transparent resin or the like, while light is shielded in the other parts by black printing. In addition, black printing is often performed on the back surface of the dial in order to prevent light from leaking out from an opening, a pointer shaft hole or the like formed in the dial or to prevent light from leaking out from between meters or display portions. In addition, white printing is generally performed on the other parts than the regions subjected to the black printing, in order to use reflection of light effectively as illumination light.
In addition, in most of recent instruments for vehicles, a liquid crystal display panel is disposed on a dial. The liquid crystal display panel is disposed on the back surface of the dial so that a display surface of the liquid crystal display panel can be visually recognized through an opening formed in the dial.
Black ink used for the black printing on the dial contains carbon black with conductivity. In addition, the black ink also contains an insulating material in addition to the carbon black. In this configuration, a part subjected to the black printing does not have conductivity as high as a metal material but has conductivity high enough to allow charges of static electricity to migrate. Accordingly, the part is characterized that charges caused by static electricity are apt to be accumulated because the charges do not migrate as quickly as that in metal.
On the other hand, the liquid crystal display panel may produce an inappropriate display due to influence of static electricity. For example, when a driver or the like touches a glass surface of the instrument for a vehicle, static electricity accumulated on the human body may flow into the liquid crystal display panel to affect display on the liquid crystal display panel.
In order to suppress static electricity from flowing into a liquid crystal display panel, Patent Literature JP-A-2009-216700 suggests that a semiconductor film is pasted onto the surface of a facing plate, and the semiconductor film is grounded. In addition, Patent Literature JP-A-2012-63305 describes an example in which static electricity flowing into a liquid crystal display panel from a glass surface is emitted to a circuit board through a flexible conductor.